The Loom of Fate is the structure on which the pattern spiders weave mystic strands of fate to set the destiny of all things. It is the most important tool of the Bureau of Destiny.
The Loom of Fate works eternally, each moment in time created in the weaving of disparate threads of primal Essence. The threads of What May Be twist and interweave in the ever-changing Now to weave the Tapestry of Creation. Created by the Primordials, it was managed by the Five Maidens and later by the Sidereal Exalted to ensure the proper flow of cause and effect in Creation. It was originally kept on the Blessed Isle, but subsequently relocated to Yu-Shan, where it occupies the five-mile-wide Lotus Dome.
Great expenditures of Essence can disrupt the Loom, and in the years leading up to the Usurpation the Loom was badly damaged by the recklessness of the Solar Exalted. One of the duties of the Sidereal Exalted is to resolve tangles in the Loom's weave, particularly those caused by agents from outside Creation -- ghosts, fae, demons, and the like.
Most of the Loom's functions are handled by pattern spiders, constructs of Autochthon. These mechanical beings spin, wind, and cut individual threats as necessary to keep order in Creation, freeing up gods and Sidereals to do more subtle work. They also alert the rest of the Bureau of tangles, especially those caused by outside actors.
Each strand in the Loom represents the fate of some entity in Creation, and touching that strand reveals that entity's destiny. Strands cannot be cut, but can be directly manipulated, such as in Sidereal Astrology, to change the destiny of a particular individual. Exalts are the most difficult to manipulate in this fashion, as every time they spend Essence they set their strand in the Loom vibrating wildly.